1. Field of the Invention
The present invention relates to a system for monitoring a location of a human by using a transmitter implanted in the human. The system may further monitor the presence of a predetermined chemical substance in the human by using an implanted substance monitoring unit. The system also controls the behavior of the human based on the monitoring by using an implanted receiver that receives a command, from a central processor such as a computer system that is analyzing the person's location or substance use, to activate an implanted behavior control unit that causes unpleasant effects in the human.
2. Description of Related Art
The overcrowding of prisons has led to the creation and use of alternative sentencing programs by the court systems. One such alternative sentence imposed is confining a prisoner in his or her home or in some other non-prison setting. This approach has led to the creation of remote monitoring systems that can determine from a centralized location whether the prisoner has left the assigned confinement area.
For example, U.S. Pat. No. 4,843,377 to Fuller et al. is directed to a remote confinement system having an external transmitter fixed at the prisoner's remote confinement area, a receiver/relaying unit and a central office computer. The central office computer identifies the prisoner and monitors the presence of a prisoner at the confinement area using information transmitted to the computer from the transmitter. The Fuller Patent also discusses other "home arrest" systems that attach bracelet radio transmitters to the prisoners. These bracelets cause an alarm to be sent to the central monitoring office via a phone transponder if the prisoner strays too far from his or her home.
One drawback of the system of the Fuller Patent and the home arrest systems disclosed therein is their fixed transmitter, which is unable to provide the monitor of the system with the prisoner's location outside the confinement area, since the transmitter merely signals his or her absence from that area. Thus, if the prisoner leaves the confinement area, his or her whereabouts will be unknown. A fixed transmitter also limits the number of confinement areas for a prisoner, as each confinement area would require installation of a transmitter. Thus, a need exists for an ambulatory transmitter that positively informs the system monitor of the location of the prisoner over a wide area so as to provide gap-free surveillance. Further, by providing coverage outside of the confinement area, an extended "confinement" area, including, for example, the prisoner's office or school, can be granted to the prisoner, which allows him or her to rehabilitate while serving his or her sentence.
Another drawback of the remote monitoring systems of the Fuller Patent is that they do not actively deter the prisoner from leaving his or her confinement area. Moreover, if the prisoner leaves the confinement area, the systems do not actively urge the prisoner to return to the confinement area, forcing the police to track down the prisoner and physically return him or her to the area. This is not only dangerous for the police and general public, but also expensive. Further, while the police are doing this, they cannot otherwise protect and serve the community. Thus, a behavior control system is needed that actively deters the prisoner from leaving the confined area, and if he or she leaves it nonetheless, urges the prisoner to return to the area.
The need for an ambulatory transmitter generally requires that the transmitter used to transmit locating signals and information regarding the prisoner's identity be externally worn by or implanted into the prisoner. Besides the above-described electronic bracelets mentioned in the Fuller Patent, externally-worn transmitters have been used to provide location signals for monitoring the locations of humans as discussed in U.S. Pat. No. 5,027,314 (Linwood et al.), U.S. Pat. No. 5,153,584 (Engira) and U.S. Pat. No. 5,218,344 (Ricketts). For example, the personnel monitoring system of the Ricketts Patent uses portable transmitter/receivers (transceivers), each of which is worn on the wrist of a person such as a prisoner within a correctional facility. Stationary transceivers interrogate all the portable transceivers, of which only the ones configured to respond to the interrogation signal reply. The portable transceivers respond to the stationary transceivers, which in turn demodulate and relay the response to a computer that determines the location and identity of each person.
Externally-worn transmitters such as those described in the Ricketts Patent, however, have several disadvantages when used in a monitoring system for monitoring prisoners outside a confined setting. They may be accidently or purposely damaged or altered. They may be removed by the prisoner and further, placed on a substitute for the prisoner to deceive the monitor.
Implanted transmitters, however, cannot so easily be damaged, altered or removed. But implanted transmitters have been primarily used for transmitting physiological parameters to a remote monitor, either in animals (U.S. Pat. No. 4,399,821 to Bowers) or humans (U.S. Pat. No. 4,677,982 to Llinas et al., U.S. Pat. No. 5,252,962 to Urbas et al. and U.S. Pat. No. 5,314,450 to Thompson), rather than transmitting signals for locating humans.
Other alternative sentences may impose certain compliance conditions on a home arrest prisoner or probationer. One such condition is ordering the prisoner to keep away from a "victim" (a protective order). A system has been created to remotely monitor compliance with a protective order (U.S. Pat. No. 5,396,227 to Carroll et al.). In the Carroll Patent, the victim keeps a sensing unit near his or her home to electronically detect the wrongful presence of the prisoner and transmit the same to a central station. Like the remote monitoring systems described above, however, the transmitting unit is stationary and thus limits the area in which the victim can safely remain.
Another condition imposed on a probationer or a home arrest prisoner is to refrain from the use of alcohol or illegal drugs. The above-described remote monitoring system of the Fuller Patent, for example, also monitors the prisoner for use of alcohol and drugs. The system includes breath alcohol and body fluid testers for determining compliance by the prisoner of the imposed substance abuse restrictions. The testers, however, are not ambulatory, and the prisoner cannot be monitored outside the fixed tester and transmitter location. This system also does not constantly test the prisoner, and thus even if the prisoner faithfully stays within the confinement area, there can be long periods of times when the prisoner's alcohol or drug use is not being monitored. Further, because the alcohol and body fluid testers are external to the prisoner, other persons can substitute their "clean" breath or fluid sample for that of the prisoner. These shortcomings allow the system to be abused. Although the system attempts to prevent this abuse by various identification measures, these methods are not foolproof and add expense and complexity to the system.
Therefore, a monitoring system having an ambulatory substance monitoring unit is needed that can monitor the use of one or more substances by the prisoner at most times and over a wide area, and does not permit substitution of another person for the prisoner or probationer. Of course, such a substance monitoring system can also be used to monitor the types and amounts of various substances present in subjects of scientific experiments without requiring the subjects to remain at a laboratory. Further, similar to the above-described need for a behavior control system for deterring a prisoner from leaving the confinement area and for urging his or her return if he or she does leave, a behavior control system is also needed for deterring a prisoner's use of unauthorized substances and for encouraging him or her to stop using the substances if he or she does use them.
A substance monitoring system generally requires the use of either an external substance monitor, with its above-described drawbacks, or an implanted monitor. Implanted monitors have been generally used for measuring physiological or biochemical parameters, for example, as described in the Bowers Patent (implanted sensors in animals for sensing blood chemistry parameters such as pH, PCO2 and PO2), the Llinas Patent (implanted sensor for measuring biochemicals) and U.S. Pat. No. 4,494,950 to Fischell (implanted glucose sensor), but not for internal monitoring of alcohol and illegal drugs.
A monitoring system may be "open-loop", that is, information flows only from the monitored person to the monitoring station. However, if behavior control based on monitoring of that person is desired, commands must be sent in a "closed-loop" manner from the monitor back to the monitored person. If this feedback is done via a radio transmitter, the commands are then received by an implanted or externally-worn radio receiver. Examples of externally-worn radio receivers are discussed in the Ricketts and Engira Patents, and implanted receivers are discussed in the Urbas, Thompson, Bowers and Llinas Patents.
Further, to control behavior, either external or internal behavior control units are required to act on command. The abdominal muscle firmness alarm of U.S. Pat. No. 4,801,921 to Zigunfus and the reminder and enforcer orthodontic apparatus of U.S. Pat. No. 4,764,111 to Knierim are two examples of external behavior control units. An implanted behavior control unit is discussed in the Fischell Patent wherein a signal is transmitted to an intracorporeal module that applies an aversive electric shock to a nerve to inhibit self-destructive behavior.
Implanted receivers, substance monitoring units and behavior control units are preferable over external devices for generally the same reasons as an implanted transmitter is preferable over an external transmitter. However, none of the above-described systems have used one or more of these implanted devices in a system that can effectively monitor or control the behavior of remotely confined prisoners or probationers.